In Generation I, the Silph Scope can be stored via PC. If it is done so, the Pokémon within the Pokémon Tower will appear as ghosts once again. The player must have the Silph Scope in their items list in order to identify the ghosts.

In the manga

Clefairy with the Silph Scope on

In the Pokémon Pocket Monsters manga

The Silph Scope first appears in Get Rid Of The Ghost Pokémon!!. Red's rival, Blue, is shown to have one and used it to identify Gengar's movements during its battle with Clefairy. However, Clefairy took the Silph Scope and used it to his advantage to defeat Gengar. Unlike its game counterpart, the Silph Scope is shaped as glasses and it was not shown to come from Silph Co..

Trivia

In Generation I, an exploit allows the player to get past the Marowak ghost without using the Silph Scope. By using a Poké Doll to flee the battle, the ghost will disappear as if it had been defeated. This allows the player to skip getting the Silph Scope and in fact skip the Rocket Hideout completely.

Also in Generation I, by viewing the status screen of a Pokémon, the ghost's sprite will change to that of the actual Pokémon. However, it still cannot be fought or caught.